1. Technical Field
This invention relates generally to mechanical and electromechanical speech aids commonly referred to as artificial larynxes, and more particularly to an improved electrically powered artificial larynx construction that significantly reduces fabrication time and expense.
2. Description of Related Art
Persons without normal use of their vocal cords or larynx often use an artificial larynx to speak. The artificial larynx produces a tone having a fundamental frequency in the speech range of the average human voice, and the user introduces this artificially generated tone into a resonant speech cavity (i.e., the mouth, nose, or pharynx). To speak, the user modulates the tone by varying the shape of the resonant speech cavity and by making the usual tongue, teeth, and lip constrictions so as to articulate the modulated tone as human speech.
U.S. Pat. No. 5,812,681 issued Aug. 28, 1998 to Clifford J. Griffin describes an ergonomically improved artificial larynx having control components that enable turn-on and frequency control with one pushbutton. Like many existing artificial larynxes, it includes a four to five-inch long cylindrically shaped case that houses a printed circuit board, a battery, an electromechanical transducer for producing vibrations (i.e., the tone), a volume control, and an on-off switch. The user grasps the case, actuates the on-off switch and volume control, and then presses the transducer against the outside of the throat so that vibrations travel through the throat tissues and into the mouth and throat. By varying pressure on the pushbutton switch, the user varies the frequency of the tone to produce a more readily comprehensible voice.
Although effective in many respects, such an artificial larynx shares a problem with other artificial larynxes. That problem is fabrication cost. Assembling all the components in the cylindrical (or other shape) case can be a time consuming and expensive task. Thus, manufacturers need an artificial larynx with details of construction designed to better reduce fabrication costs.